1. Field of the Invention
The present invention relates to an apparatus and method for the purification of contaminated water whereby the contamination level of the contaminated water is automatically monitored and treatment self-adjusted and continued until the desired level of purification is reached. Specifically, if upon treatment a preset purification level is not obtained a water recycle control means completely precludes the uptake of additional contaminated water and recycles the contaminated water within the apparatus until the desired level of purification is obtained. The present invention more particularly pertains to an efficient, turn key economical, movable, automatic and compact apparatus and method for treating a fluid with ozone comprising multiple pressurized contact columns which are arranged in a hybrid parallel and series column configuration, which utilizes a unique water recycle control system and piping arrangement to improve the efficiency of the mass transfer of ozone into the water and increase its solubility by increasing the pressure and contact time between the water phase and the gas phase. The apparatus and method of the present invention has the further advantage that it requires minimal installation and may be used to fulfill the clean and safe water needs of any hotel, resort, restaurant, hospital, light industry, commercial business, apartment complex or small city. Another application is to deactive waters from biologically active digestion prior to discharge or reuse.
2. Description of the Background Art
Presently there exist many types of water purification devices designed to treat water and wastewater with ozone. As a general background there are a number of problems inherent in the use of ozone as a method of water treatment, in particular, ozone gas is very reactive and unstable with a half life in water measured in minutes, it is unstable in a low pressure environment especially if there is too much agitation, heat and ultraviolet light. Large quantities of ozone are difficult to generate at low cost.
Continuing efforts are being made to improve water treatment methods and apparatus. Consider background patents which illustrate, for example, the large number of water purification techniques such as in U.S. Pat. No. 5,178,755, issued to LaCrosse, that discloses a method for treating wastewater, that has been enhanced by treatment with ultra-violet light and with ozone. In this system, a large amount of ozone is generated and inserted at several points in the effluent flow, including insertion in each of the three clarifiers. This system utilizes large quantities of ozone at a relatively high cost and low efficiency. Furthermore, in this system; water is continually re-circulated based upon a timer and the system does not automatically respond to changes in the influent quality or discharge water from the system based upon water quality parameters.
It is also well known to pass the polluted water through specialized filters. See for instance, U.S. Pat. No. 4,798,669, issued to Bachhofer, et al., that discloses an apparatus for mixing the ozone with water which is then trickled over packing material to entrain the ozone within the water being treated. The water is re-circulated through a return branch and mixes with the incoming contaminant water before it enters the treatment system. The re-circulation step is not automatic or self-adjusting based upon water quality parameters. Further ozone contact with the contaminants, after filtration of the effluent, is made by inserting recaptured gas into the effluent stream prior to the effluent being treated by a packed column which trickles the effluent over a packing material. As agitation reduces the capability of water to retain ozone, trickling over packing material may be detrimental to the efficient retention of ozone within the effluent for effective contact with contaminants. See additionally, U.S. Pat. No. 5,466,374 to Bachhofer et al.
U.S. Pat. No. 5,207,993 to Burris discloses a liquid purifier for the treatment of batches of liquid less than twenty (20) liters in size. The purifier of Burris may be configured to incorporate a circulation loop such that treated liquid may be returned to the reservoir for storage after treatment. The patent to Burris contemplates a limited control system and sensor that operates to notify the operator if the ozone generator is operating. Burris does not disclose automatic re-circulation via water quality controllers rather by operational parameters.
U.S. Pat. No. 3,945,918, issued to Kirk; U.S. Pat. No. 5,273,664, issued to Schulz and U.S. Pat. No. 5,376,266, issued to Broussard all disclose treatment chambers that are open to one another. In Kirk, the wastewater is passed over a plurality of weirs that agitate the water to aerate it. The gas that is not absorbed within the effluent is collected and reinserted upstream to obtain further contact time. This is a complex system requiring numerous tanks and weirs which may denigrate the ozone retention within the wastewater. Schulz uses a plurality of open chambers that are connected by transfer conduits. The ozone is fed into the transfer conduits to entrain and mix the ozone with the water as it passes therethrough. The water then passes into the treatment chambers through a venturi-mixing chamber. The free ozone and other gases are vented through a conduit for treatment and disposal. The gases are not reused. In an alternative embodiment, separate vessels are used and the ozone is diffused directly into the water as it flows through the connecting pipes between the vessels. Additionally, Broussard teaches a multi-stage separator vessel utilized as an oil/water separator.
Another grouping of background patents are those which disclose the use of multiple serially connected reactors or stripper columns. By way of example, U.S. Pat. No. 4,696,739 to Pedneault teaches an apparatus which utilizes a plurality of tubular chambers (stripper columns) which are connected in series to strip hydrocarbon contaminants. Pedneault discloses utilizing air flowing counter-currently, optionally containing ozone and optionally heated, through serially connected columns to remove volatile hydrocarbons. Pedneault does not disclose recirculation of water to achieve water quality parameters. U.S. Pat. No. 5,498,347 to Richard teaches use of contact tanks connected in series in which the oxidizing action of ozone is intensified by the introduction of hydrogen peroxide. See also U.S. Pat. Nos. 5,397,480 and 5,458,789 to Dickerson et al.
U.S. Pat. No. 5,336,413 to van Staveren teaches the use of a gas collection device to separate ozone/oxygen from water so that gas does not cavitate and impede the operation of a pump in a water purification apparatus. The apparatus of van Staveren does not teach the re-circulation of water to ensure the attainment of water quality parameters. Rather, van Staveren discloses to re-cycle the waste stream to prevent the discharge of toxic waste.
In short, water purification is customarily accomplished by vessels connected in serial fluid communication with one another without a means for self-monitoring and preclusion of incoming contaminating fluid to ensure that one-hundred percent of the water discharged from the apparatus meets certain water quality parameters. Generally speaking, the injection of ozone into the contaminated water stream deactivates and destroys bacteria and viruses, causes inorganic contaminants to oxidize to less soluble oxides and converts organic components to carbonaceous residues and carbon dioxide. Known apparatuses have utilized ozone injectors to introduce ozone in the form of a vast quantity of microscopic bubbles which tend to form about the suspended solid particles and float those particles to the surface of a body of liquid.
However, these known purification apparatuses have drawbacks. Due to the particular arrangement of the various components within, the size of the purification apparatus is often presented as a particular burdensome drawback. Additionally, utilization of columns connected in series may not maximize the absorption of ozone into a contaminated water stream. Additionally, known purification apparatuses do not automatically adjust to changes in the quality of the contaminated water and adapt from continuous operation to batch operation, thereby increasing contact time, until treatment parameters are met. Although some background patents teach to increase ozone production if the contaminated water is not sufficiently purified, it must be borne in mind that the ozone generator will have a maximum capacity based upon its original size such that if the contaminate level of the water is greatly increased, and the ozone generator is working at its full capacity, water may not be completely treated.
Not withstanding the existence of such prior art treatment systems, it remains clear there is a need for a water treatment system that is simple, portable, and efficiently uses the generated ozone in the treatment of the water.
In as much as the art consists of various types of purification apparatus and ozone column configurations, it can be appreciated that there is a continuing need for and interest in improvements to purification systems and their configurations, and in this respect, the present invention addresses these needs and interests.
Therefore, the principal object of this invention is to provide an improvement that overcomes the aforementioned inadequacies of the prior art devices and provides an improvement that is a significant contribution to the advancement of the purification art.
Another object of this invention is to provide a new and improved purification apparatus which has all the advantages and none of the disadvantages of the earlier water purification apparatus.
In response to the realized inadequacies of earlier configurations of water purification apparatus and systems, an apparatus and method for treating a fluid with ozone comprising multiple pressurized contact columns which are arranged in a hybrid parallel and series column configuration, which utilizes a unique water recycle control system and piping arrangement to improve the efficiency of the mass transfer of ozone into the water and increase its solubility and contact time between the water phase and the gas phase was developed.
Still a further objective of the present invention is to provide a water recycle control means to determine and control whether the treated water should be recycled through the water purification process, to the exclusion of fresh untreated water.
Yet another objective of the present invention is improved efficiency of dissolving or forcing a gas (ozone) into the flow of contaminated water using multiple pressurized contact columns.
Still another objective of the present invention is to provide a compact, turnkey, movable, water purification apparatus which may be easily transportable, and easily moved to a different location within the area of operation.
Yet a further objective is to allow for increased contact time of the contaminated water within the columns thereby increasing contaminant removal and purification.
An additional objective is to provide an ozone purification system that is highly reliable in use and easy to operate, monitor and maintain and minimizes the likelihood of operator error.
Another objective is to provide a ozone purification system which effectively neutralizes specific organisms which are responsible for infectious diseases, including but not limited to shigella dysenteriae, salmonella, escherichia coli, klebsiella pneumoniae, vibrio cholerae, giardia spp., cryptosporidium spp. and entamoeba histolytica.
Another objective is to provide an ozone purification system which requires little energy consumption.
Another objective is to provide an ozone purification system which is ecologically safe and minimizes the use of extraneous chemicals and additives.
Another objective is to provide an ozone purification system which may be sized to meet a wide range of flow requirements from a number of contaminated water sources either as in-line treatment or as a side stream apparatus.
Even yet another objective is to provide a water purification system which utilizes modular components.
An additional objective is to provide a compact and moveable purification apparatus that may be easily incorporated into any existing water purification system containing other treatment units such as filters (including sand, carbon, or multimedia), dissolved air flotation (DAF), coagulation/flocculation basins, sedimentation basins, storage tanks, or any combination thereof.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and a more comprehensive understanding of the invention may be obtained by referring to the summary of the invention, and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.